Air Quality Testing

written by: Matt Schelke•edited by: Niki Fears•updated: 12/15/2008

Air quality testing is more important today than ever before. Discover how it's done and why it matters.

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What do you do to stay healthy? Many people eat organic foods, wash their hands, get fresh air, and sleep well at night. But how about breathing well? Airborne diseases and pollutants are as harmful as those carried by food and water. So what can you do about these “invisible killers”?

The problem with airborne pollutants and particulates is that you can’t control them. Viruses can float in through windows. doors, and any open seam. Asthma-causing dust can enter your lungs whenever you suck in some air. But does this mean that you should stop breathing or that all air is deadly? Of course not- in fact, most air is healthy, good air. It means you should test your air quality regularly.

Most air pollution is either organic or inorganic. Organic pollution includes molds and bacteria; these organisms float through the air until they find a suitable surface on which to attach and grow. Inorganic pollution includes dust and chemicals like formaldehyde. These particles can enter your lungs and cause serious respiratory problems. While both organic and inorganic pollution are dangerous, they are tested in very different ways.

Organic pollution is tested using petri dishes and growth mediums. A quantity of air is collected, either by physically forcing it into a container or by allowing it to flow through a sampling machine. If there are any organic materials in the air, they will attach to the medium (usually a form of agar gel) in the dish and grow, forming colonies. The colonies can then be identified and the sources of the organisms can be removed.

Inorganic pollution, like dust and particles (called aerosols), won’t attach to petri dishes and thus is monitored using a method called photometry. Essentially, this involves shining a light through a quantity of air and measuring either the strength of the light as it passes through the air or the refracted rays as the light is scattered by aerosols. If there are many particles, the light will be weak and scattered widely.

Air quality testing is more important now than ever before. As industry reaches more and more parts of the globe, pollution goes up. The problem with air pollution is that it can travel anywhere- a factory in the South Pacific can affect the air in Maine. Testing is thus key to a healthy life and a healthy world.